KR20160064323A - Liquid crystal display - Google Patents

Abstract

A liquid crystal display according to an embodiment of the present invention includes: a first substrate; a gate line formed on the first substrate; an insulating film formed on the gate line; and a first sub-pixel electrode and a second sub-pixel electrode including a plurality of pixel branched electrodes, wherein each of the first sub-pixel electrode and the second sub-pixel electrode includes a first region and a second region. The first region and the second region of the first sub-pixel electrode have a polygonal shape where two sides meet diagonally. One side which is not a diagonal of the polygon is located vertically to the gate line. The first region and the second region of the second sub-pixel electrode form a groove of the shape corresponding to the first sub-pixel electrode to the one side. The first sub-pixel electrode is connected to the first region and the second region, respectively. The first region and the second region of the second sub-pixel electrode can be connected to each other. The present invention is designed to provide a display device which does not generate a texture when bending.

Description

[0001] LIQUID CRYSTAL DISPLAY [0002]

The present invention relates to a liquid crystal display device.

2. Description of the Related Art [0002] A liquid crystal display device is one of the most widely used flat panel display devices, and includes two display panels having field generating electrodes such as a pixel electrode and a common electrode, and a liquid crystal layer interposed therebetween. The liquid crystal display displays an image by applying a voltage to the electric field generating electrode to generate an electric field in the liquid crystal layer, thereby determining the direction of the liquid crystal molecules in the liquid crystal layer and controlling the polarization of the incident light.

Of the liquid crystal display devices, a vertically aligned mode liquid crystal display device in which the long axes of liquid crystal molecules are arranged perpendicular to the upper and lower display panels in the absence of an electric field has been spotlighted because of a large contrast ratio and a wide viewing angle. .

In order to realize a wide viewing angle in such a vertical alignment mode liquid crystal display, a plurality of domains having different directions of liquid crystal alignment can be formed in one pixel.

As such a means for forming a plurality of domains, a method such as forming a cut-out portion such as a fine slit in the electric field generating electrode or forming a protrusion on the electric field generating electrode is used. This method can form a plurality of domains by orienting the liquid crystal in a direction perpendicular to the fringe field by a fringe field formed between an edge of the cutout or protrusion and the electric field generating electrode facing the electrode .

SUMMARY OF THE INVENTION The present invention is directed to a display device in which side visibility is improved and a texture is not generated when bent.

According to an aspect of the present invention, there is provided a liquid crystal display device including a first substrate, a gate line formed on the first substrate, an insulating film formed on the gate line, Pixel electrode and a second sub-pixel electrode, wherein the first sub-pixel electrode and the second sub-pixel electrode each include a first region and a second region, and the first region and the second region of the first sub- 2 region is a polygonal shape in which two sides meet diagonally with each other, one side of the polygon not perpendicular to the gate line is positioned perpendicular to the gate line, and the first region and the second region of the second sub- Pixel electrode, wherein the first sub-pixel electrode is connected to the first region and the second region is connected to the first sub-pixel electrode, and the first region and the second region of the second sub-pixel electrode are connected to each other connect It can control.

The first sub-pixel electrode may include a vertical portion perpendicular to the gate line, a horizontal portion connected to the vertical portion and perpendicular to the vertical portion, and a plurality of fine branch portions extending in both diagonal directions from the horizontal portion. have.

The length of the fine branching portion may be the longest near the vertical branching portion and may be gradually shortened away from the vertical branching portion.

The vertical stripe portion of the first region of the first sub-pixel electrode and the vertical stripe portion of the second region of the first sub-pixel electrode may be located opposite to each other.

The vertical stripe portion of the first region of the first sub-pixel electrode and the vertical stripe portion of the second region of the first sub-pixel electrode may be located on the same side.

An extension line extending across the first area of the second sub-pixel electrode is formed in the first area of the first sub-pixel electrode, and the extended line may be connected to the second area of the first sub-pixel electrode.

A first drain electrode and a second drain electrode formed on the insulating film; a protection film formed on the first drain electrode and the second drain electrode, the protection film including a first contact hole exposing the first drain electrode, Pixel electrode and the second region of the first sub-pixel electrode are formed on the first contact hole through the first contact hole, the second contact hole is formed to expose the drain electrode, and the extension line connecting the first region of the first sub- Drain electrode.

The second sub-pixel electrode includes a vertical portion perpendicular to the gate line, a plurality of horizontal portions connected to the vertical portion and perpendicular to the vertical portion, and a plurality of fine branched portions extending in both diagonal directions from the horizontal portion .

The plurality of transverse portions in the first region or the second region of the second sub-pixel electrode are respectively located at the upper, middle, and lower portions of the respective regions, and the lengths of the transverse portions located at the upper and lower portions, Can be longer than the length of the part.

The horizontal portion located at the center portion may be removed in the first region or the second region of the second sub-pixel electrode.

The vertical stripe portion of the first region of the second sub-pixel electrode and the vertical stripe portion of the second region of the second sub-pixel electrode may be located opposite to each other.

The vertical stripe portion of the first region of the second sub-pixel electrode and the vertical stripe portion of the second region of the second sub-pixel electrode may be located on the same side.

The first region of the second sub-pixel electrode and the second region of the second sub-pixel electrode are connected by an extension line of the second sub-pixel electrode, and an extension line of the second sub- Or may proceed across an area where the gate line is formed.

A first drain electrode and a second drain electrode formed on the insulating film; a protection film formed on the first drain electrode and the second drain electrode, the protection film including a first contact hole exposing the first drain electrode, Pixel electrode and the second region of the second sub-pixel electrode is connected to the second contact hole through the second contact hole, and the second contact hole is formed to expose the drain electrode, and an extension line connecting the first region of the second sub- And may be in contact with the electrode.

A second substrate corresponding to the first substrate, a common electrode formed on the second substrate, and a liquid crystal layer disposed between the first substrate and the second substrate, wherein a magnitude of a voltage applied before the first sub- And the voltage applied to the second sub-pixel electrode may be different from each other.

Wherein the alignment layer is formed on the first sub-pixel electrode and the second sub-pixel electrode, the alignment layer is formed on the alignment layer at an angle, and a line inclination angle formed in the alignment layer on the first sub- May be greater than the line inclination angle formed in the alignment film on the sub-pixel electrode.

The first sub-pixel electrode and the second sub-pixel electrode may not overlap with each other.

The liquid crystal display device may be a curved display.

The first region may be located above the gate line, and the second region may be located below the gate line.

The first region and the second region of the first sub-pixel electrode are in the shape of a triangle, and the first region and the second region of the second sub-pixel electrode have triangular grooves corresponding to the first sub- And may be formed in a rectangular shape.

As described above, in the display device according to the embodiment of the present invention, the first sub-pixel electrode and the second sub-pixel electrode are present on both sides with respect to the gate line, thereby improving lateral visibility and realizing a curved display , The problem of the occurrence of the texture is solved.

1 is an equivalent circuit diagram of one pixel of a liquid crystal display according to an embodiment of the present invention.
2 is a layout diagram of an example of a pixel of a liquid crystal display device according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of the liquid crystal display of FIG. 2 taken along line III-III.
FIG. 4 shows only the pixel electrodes separately in the arrangement diagram of FIG. 2. FIG.
FIG. 5 illustrates a pixel electrode according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 6 is a view showing a process of making a liquid crystal molecule have a line inclination by using a prepolymer polymerized by light such as ultraviolet light.
7 is a layout diagram of a display device according to a comparative example of the present invention.
8 is an image in which a texture is generated in a display device having a pixel structure according to a comparative example of the present invention.
9 is an image of a display device according to an embodiment of the present invention.
FIG. 10 shows a result of a visibility simulation according to a display device and a comparative example according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

First, with reference to FIG. 1, the arrangement of signal lines and pixels and the driving method thereof in a liquid crystal display device according to an embodiment of the present invention will be described. 1 is an equivalent circuit diagram of one pixel of a liquid crystal display according to an embodiment of the present invention.

1, a pixel PX of the liquid crystal display according to the present embodiment includes a gate line GL for transferring a gate signal and a data line DL for transferring a data signal, A plurality of signal lines including a reference voltage line RL and first, second and third switching elements Qa, Qb and Qc connected to a plurality of signal lines, first and second liquid crystal capacitors Clca and Clcb, .

The first and second switching elements Qa and Qb are connected to the gate line GL and the data line DL respectively and the third switching element Qc is connected to the output terminal of the second switching element Qb, And is connected to the reference voltage line RL.

The first switching element Qa and the second switching element Qb are three terminal elements such as a thin film transistor and the control terminal thereof is connected to the gate line GL and the input terminal is connected to the data line DL The output terminal of the first switching device Qa is connected to the first liquid crystal capacitor Clca and the output terminal of the second switching device Qb is connected to the second liquid crystal capacitor Clcb and the third switching device Qc As shown in Fig.

The third switching element Qc is also a three terminal element such as a thin film transistor. The control terminal is connected to the gate line GL. The input terminal is connected to the second liquid crystal capacitor Clcb. And is connected to the voltage line RL.

When a gate-on signal is applied to the gate line GL, the first switching device Qa, the second switching device Qb, and the third switching device Qc connected thereto are turned on. The data voltage applied to the data line DL is applied to the first sub-pixel electrode PEa and the second sub-pixel electrode PEb through the turned-on first switching device Qa and the second switching device Qb. . At this time, the data voltages applied to the first sub-pixel electrode PEa and the second sub-pixel electrode PEb are the same, and the first liquid crystal capacitor Clca and the second liquid crystal capacitor Clcb are common voltages and data voltages As shown in Fig. At the same time, the voltage charged in the second liquid crystal capacitor Clcb is divided through the third switching element Qc turned on. As a result, the voltage value charged in the second liquid crystal capacitor Clcb is lowered by the difference between the common voltage and the divided voltage reference voltage. That is, the voltage charged in the first liquid crystal capacitor Clca becomes higher than the voltage charged in the second liquid crystal capacitor Clcb.

As described above, the voltage charged in the first liquid crystal capacitor Clca and the voltage charged in the second liquid crystal capacitor Clcb are different from each other. Since the voltage of the first liquid crystal capacitor Clca and the voltage of the second liquid crystal capacitor Clcb are different from each other, the inclination angles of the liquid crystal molecules in the first sub-pixel and the second sub-pixel are different, It is different. Accordingly, by appropriately adjusting the voltage of the first liquid crystal capacitor Clca and the voltage of the second liquid crystal capacitor Clcb, the image viewed from the side can be made as close as possible to the image viewed from the front side, .

In the illustrated embodiment, in order to make the voltage charged in the first liquid crystal capacitor Clca different from the voltage charged in the second liquid crystal capacitor Clcb, the second liquid crystal capacitor Clcb is connected to the second liquid crystal capacitor Clcb and the divided voltage reference line RL 3 switching element Qc. However, in the case of the liquid crystal display according to another embodiment of the present invention, the second liquid crystal capacitor Clcb may be connected to the step-down capacitor. Specifically, the liquid crystal display device includes a third switching element including a first terminal connected to the voltage-sensitive gate line, a second terminal connected to the second liquid crystal capacitor (Clcb), and a third terminal connected to the reduced- May be charged in the decompression capacitor to set the charging voltage between the first liquid crystal capacitor Clcb and the second liquid crystal capacitor Clcb to be different from each other. In the liquid crystal display device according to another embodiment of the present invention, the first liquid crystal capacitor Clcb and the second liquid crystal capacitor Clcb are connected to different data lines to receive different data voltages , And the charging voltage between the first liquid crystal capacitor Clcb and the second liquid crystal capacitor Clcb may be set differently. In addition, the charging voltage between the first liquid crystal capacitor Clcb and the second liquid crystal capacitor Clcb can be set differently by various other methods.

Hereinafter, the structure of the liquid crystal display device according to the embodiment shown in FIG. 1 will be briefly described with reference to FIGS. 2 to 5. FIG. FIG. 2 is a layout view of an example of a pixel of a liquid crystal display device according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along a line III-III of the liquid crystal display device of FIG. FIG. 4 shows only the pixel electrodes separately in the arrangement diagram of FIG. 2. FIG. FIG. 5 illustrates a pixel electrode according to an exemplary embodiment of the present invention. Referring to FIG.

2 and 3, the liquid crystal display according to the present embodiment includes a lower panel 100 and an upper panel 200 facing each other, a liquid crystal layer (not shown) between the two panels 100 and 200 3 and a pair of polarizers (not shown) attached to the outer surfaces of the display panels 100, 200.

First, the lower panel 100 will be described.

A gate conductor including a gate line 121 and a divided voltage reference line 131 is formed on an insulating substrate 110 made of transparent glass or plastic.

The gate line 121 crosses one pixel region and distinguishes between a first region A located above the gate line 121 and a second region B located below the gate line.

Gate line 121 passing region is a transistor or the like is formed in the light shielding by the black matrix or the like after, which is referred to as a thin film transistor region (C).

The gate line 121 includes a first gate electrode 124a, a second gate electrode 124b, a third gate electrode 124c, and a wide end (not shown) for connection to another layer or an external driving circuit .

The divided voltage reference line 131 includes first sustain electrodes 135 and 136, and a reference electrode 137. The second sustain electrodes 138 and 139 are positioned below the gate line 121 although not connected to the voltage division line 131. [

A gate insulating film 140 is formed on the gate line 121 and the divided voltage reference line 131.

A first semiconductor 154a, a second semiconductor 154b, and a third semiconductor 154c are formed on the gate insulating film 140. The first semiconductor 154a, the second semiconductor 154b,

A plurality of resistive contact members 163a, 165a, 163b, 165b, 163c, and 165c are formed on the semiconductors 154a, 154b, and 154c.

A plurality of data lines 171 including a first source electrode 173a and a second source electrode 173b are formed on the resistive contact members 163a, 165a, 163b, 165b, 163c and 165c and the gate insulating film 140, A data conductor including a first drain electrode 175a, a second drain electrode 175b, a third source electrode 173a, and a third drain electrode 175c is formed.

The data conductor and underlying semiconductor and resistive contact members may be formed simultaneously using a single mask.

The data line 171 includes a wide end portion (not shown) for connection with another layer or an external driving circuit.

The first gate electrode 124a, the first source electrode 173a and the first drain electrode 175a together with the first island semiconductor 154a form a first thin film transistor (TFT) Qa A channel of the thin film transistor is formed in the semiconductor 154a between the first source electrode 173a and the first drain electrode 175a. Similarly, the second gate electrode 124b, the second source electrode 173b, and the second drain electrode 175b together with the second island-shaped semiconductor 154b form one second thin film transistor Qb, The third gate electrode 124c, the third source electrode 173c and the third drain electrode 175c are formed in the semiconductor 154b between the second source electrode 173b and the second drain electrode 175b. The third island-shaped semiconductor 154c forms a third thin film transistor Qc, and a channel is formed in the semiconductor 154c between the third source electrode 173c and the third drain electrode 175c.

The second drain electrode 175b is connected to the third source electrode 173c and includes a widened extension 177. [

A first protective film 180p is formed on the portions of the data conductors 171, 173c, 175a, 175b, and 175c and exposed semiconductors 154a, 154b, and 154c. The first protective film 180p may include an inorganic insulating film such as silicon nitride or silicon oxide. The first protective film 180p can prevent the pigment of the color filter 230 from flowing into the exposed portions of the semiconductors 154a, 154b, and 154c.

A color filter 230 is formed on the first protective film 180p. The color filter 230 extends vertically along two adjacent data lines. However, in another embodiment of the present invention, the color filter 230 may be present on the top substrate.

A second passivation layer 180q is formed on the color filter 230.

The second protective film 180q may include an inorganic insulating film such as silicon nitride or silicon oxide. The second protective film 180q prevents the color filter 230 from being lifted and suppresses contamination of the liquid crystal layer 3 due to an organic matter such as a solvent introduced from the color filter 230, It prevents defects such as afterimages.

A first contact hole 185a and a second contact hole 185b for exposing the first drain electrode 175a and the second drain electrode 175b are formed in the first protective film 180p and the second protective film 180q. Respectively.

A third contact hole 185c is formed in the first protective film 180p and the second protective film 180q and the gate insulating film 140 to expose a part of the reference electrode 137 and a part of the third drain electrode 175c And the third contact hole 185c is covered with the connecting member 195. The connection member 195 electrically connects the third drain electrode 175c with the reference electrode 137 exposed through the third contact hole 185c.

A plurality of pixel electrodes 191 are formed on the second passivation layer 180q.

Each of the pixel electrodes 191 is separately provided in the A region and the B region, and is also separated in one of the regions A and B.

Referring to FIGS. 2 and 4, the pixel electrode is divided into a first sub-pixel electrode 191a and a second sub-pixel electrode 191b.

The first sub-pixel electrode 191a is separated from the A region and the B region, and the first sub-pixel electrode 191ah of the A region and the first sub-pixel electrode 191al of the B region are formed in the thin- (C).

Similarly, the second sub-pixel electrode 191b exists separately in the A region and the B region, and the second sub-pixel electrode 191bh of the A region and the second sub-pixel electrode 191bl of the B region are separated from each other in the thin- (C).

The shape of the pixel electrode according to one embodiment of the present invention will now be described in detail with reference to FIG.

First, the first sub-pixel electrode 191ah and the second sub-pixel electrode 191bh in the A region are formed by separating spaces in a diagonal direction from the data line. That is, the first sub-pixel electrode 191 ah is formed in an isosceles triangle shape having a base line in a direction parallel to the data line. On the other hand, the second sub-pixel electrode 191bh is formed in a rectangular shape having a V-shaped groove surrounding the triangle of the first sub-pixel electrode 191ah.

At this time, the first sub-pixel electrode 191 ah includes a horizontal stripe portion 192a and a fine branch portion 193a extending therefrom. The transverse stem 192a is orthogonal to the longitudinal stem base 195a formed at one end and the fine stem 193a extending from the transverse stem 192a extends upward and downward in the diagonal direction from the transverse stem 192a It stretches out.

Similarly, the first sub-pixel electrode 191al of the B region also includes the horizontal stripe portion 192a and the fine branch portion 193a extending therefrom. The transverse stem 192a is orthogonal to the longitudinal stem base 195a formed at one end and the fine stem 193a extending from the transverse stem 192a extends upward and downward in the diagonal direction from the transverse stem 192a It stretches out.

5A, the vertical stripe portion 195a of the first sub-pixel electrode 191ah of the A region and the vertical stripe portion 195a of the first sub-pixel electrode 191al of the B region are connected to each other It is located on the opposite side. However, in another embodiment, as shown in Fig. 5B, the vertical stripe portion 195a of the first sub-pixel electrode 191ah of the A region and the vertical stripe portion 195a of the first sub-pixel electrode 191al of the B region 195a may be located on the same side.

The first sub-pixel electrode 191ah in the A region and the first sub-pixel electrode 191al in the B region are connected to each other in the transistor region C. The connection form may be various and may be connected in the form of FIG. 4 in one embodiment, but it is not limited thereto. Concrete connection forms will be described later.

Referring again to FIG. 5, the second sub-pixel electrode 191bh of the A region is formed to surround the first sub-pixel electrode 191ah. That is, it has a polygonal shape in which a triangular groove having the same shape as the first sub-pixel electrode 191 ah is formed.

The second sub-pixel electrode 191bh of the A region also includes the horizontal line bases 192b and 194b and the vertical line bases 195b orthogonal to the horizontal line bases and the fine branched lines 193b extending in the diagonal direction from the horizontal line bases .

In the case of the second sub-pixel electrode, there may be a total of three lateral stem portions including a horizontal stem portion 192b positioned at the center and two horizontal stem portions 194b positioned at both edges.

However, in order to connect the second sub-pixel electrode 191bh of the A region and the second sub-pixel electrode 191bl of the B region as shown in FIG. 4, a part of the transverse stem may be removed.

The shape of the second sub-pixel electrode 191bl in the B region is also the same as the shape of the second sub-pixel electrode 191bh in the A region. A detailed description of the same components will be omitted.

5A, the vertical stripe portion 195b of the second sub-pixel electrode 191bh of the A region and the vertical stripe portion 195b of the second sub-pixel electrode 191h1 of the B region are formed on the opposite sides . However, as shown in FIG. 5B, the vertical streak portions of the second sub-pixel electrodes 191bh in the region A and the vertical streak portions of the second sub-pixel electrodes 191bl in the B region may be located on the same side .

Referring to FIG. 5, both the first sub-pixel electrode 191a and the second sub-pixel electrode 191b have a vertical stripe portion and a transverse stripe portion orthogonal to the first vertical stripe portion and have a fine branch portion extending from the horizontal stripe portion. In this case, since the spaces are separated by the sloped lines by the first sub-pixel electrode and the second sub-pixel electrode, the length of the fine branches of the first sub-pixel electrode and the second sub-pixel electrode is It is not the same.

That is, when the first sub-pixel electrode 191ah is taken as an example, the length of the fine branch portion 193a adjacent to the vertical branch base portion 195a is long, but the length of the fine branch portion of the portion apart from the vertical branch base portion is shortened. Conversely, in the case of the second sub-pixel electrode 191bh, the length of the fine branch portion 193b adjacent to the vertical stripe portion 195a is the shortest, and the length of the fine branch portion 193b is shortened again.

That is, the lengths of the fine branches in one sub-pixel electrode are not the same. As will be described later, this improves the texture problem caused by such a truncated-sided pixel electrode structure. In the case of the display device having the electrode structure of the fine branch portions extending from the vertical line base portion, the horizontal line base portion orthogonal to the horizontal line base portion and the horizontal line base portion, texture is generated because the control power of the liquid crystal is different depending on the position.

However, in the case of the display device having the electrode structure as in the present invention, the length of the fine branches varies depending on the position, and the liquid crystal strengthens the control force in the region where the control force is insufficient. Therefore, the occurrence of such a texture can be prevented.

The pixel electrode 191 may be made of a transparent material such as ITO and IZO. The pixel electrode 191 may be made of a transparent conductive material such as ITO or IZO, or a reflective metal such as aluminum, silver, chromium, or an alloy thereof.

The first sub pixel electrode 191a and the second sub pixel electrode 191b are electrically connected to the first drain electrode 175a and the second drain electrode 175b through the first contact hole 185a and the second contact hole 185b, And a data voltage is applied from the first drain electrode 175a and the second drain electrode 175b. At this time, a part of the data voltage applied to the second drain electrode 175b is divided through the third source electrode 173c so that the magnitude of the voltage applied to the first sub- Is greater than the magnitude of the voltage applied to the capacitor 191b.

The connection form of the first sub-pixel electrode and the second sub-pixel electrode in each region will be described with reference to FIG.

2 and 4, the transverse stripe portion 192a of the first sub-pixel electrode 191ah of the A region proceeds across the center of the second sub-pixel electrode 191bh, . In the transistor region C, the first sub-pixel electrode extension portion contacts the first drain electrode 175a through the first contact hole 185a. The first sub-pixel electrode extension extends downward and is connected to the first sub-pixel electrode 191al of the B region. Accordingly, the voltage applied to the first drain electrode is transmitted to both the first sub-pixel electrode 191ah of the A region and the first sub-pixel electrode 191al of the B region.

The second sub-pixel electrode 191bh of the A region is formed with a groove in the center for connection of the first sub-pixel electrode. The second sub-pixel electrode 191bh of the A region thus separated is connected to each other through an extension of the second sub-pixel electrode extending outside the first sub-pixel electrode 191ah. In addition, the extension extends to the B region and is connected to the second sub-pixel electrode 191bl in the B region. The second sub-pixel electrode 191bh of the A region and the second sub-pixel electrode 191bl of the B region are physically and electrically connected to the second drain electrode 191 through the second contact hole 185b with extension lines, respectively So that the voltage is supplied. As described above, a part of the data voltage applied to the second drain electrode 175b is divided through the third source electrode 173c, and the magnitude of the voltage applied to the first sub-pixel electrode 191a is divided by the second Is larger than the voltage applied to the sub-pixel electrode 191b.

Therefore, the liquid crystal in the region corresponding to each first sub-pixel electrode is different from the liquid crystal in the region corresponding to the second sub-pixel electrode, thereby improving lateral visibility.

The first sub-pixel electrode 191a and the second sub-pixel electrode 191b to which the data voltage is applied generate an electric field together with the common electrode 270 of the upper panel 200, The direction of the liquid crystal molecules of the layer 3 is determined. The luminance of the light passing through the liquid crystal layer 3 varies depending on the orientation of the liquid crystal molecules thus determined.

Now, the upper display panel 200 will be described.

A light blocking member 220 is formed on an insulating substrate 210 made of transparent glass or plastic. The light shielding member 220 is also called a black matrix and blocks light leakage. However, the light shielding member 220 of the upper panel 200 may be formed on the lower panel 100.

An overcoat 250 is formed on the light shielding member 220. The cover film 250 may be made of (organic) insulating material, and the cover film 250 may be omitted.

An alignment film (not shown) may be disposed on the cover film 250.

The liquid crystal layer 3 has a negative dielectric anisotropy and the liquid crystal molecules of the liquid crystal layer 3 are oriented such that their long axes are perpendicular to the surfaces of the two display panels 100 and 200 in the absence of an electric field.

Next, a method of initial alignment so that the liquid crystal molecules 31 have a line inclination will be described with reference to FIG.

FIG. 6 is a view showing a process of making a liquid crystal molecule have a linear gradient by using a prepolymer polymerized by light such as ultraviolet light.

A prepolymer 33 such as a monomer which is cured by polymerization by light such as ultraviolet light is injected between the two display panels 100 and 200 together with the liquid crystal material. The whole polymer (33) may be a reactive mesogen which undergoes a polymerization reaction with light such as ultraviolet rays.

Next, a data voltage is applied to the first sub-pixel electrode 191a and the second sub-pixel electrode 191b and a common voltage is applied to the common electrode 270 of the upper display panel 200 to apply a voltage between the two display panels 100 and 200 An electric field is generated in the liquid crystal layer 3 of FIG.

At this time, different voltages are applied to the first sub-pixel electrode and the second sub-pixel electrode. A voltage higher than that of the second sub-pixel electrode is applied to the first sub-pixel electrode, so that the liquid crystal corresponding to the first sub-pixel electrode and the liquid crystal corresponding to the second sub-pixel electrode are different from each other.

Next, when light such as ultraviolet rays is irradiated, the prepolymer 33 undergoes a polymerization reaction to form a polymer 370 as shown in FIG. The polymer 370 is formed in contact with the display plates 100 and 200. The liquid crystal molecules 31 have a line inclination due to the polymer 370, and the line inclination angle becomes proportional to the intensity of the applied electric field. That is, the line pretilt of the liquid crystal in the region corresponding to the first sub-pixel electrode is larger than the line inclination of the liquid crystal in the region corresponding to the second sub-pixel electrode.

The effect of the display device according to an embodiment of the present invention will be described by comparison with the comparative example of the present invention.

7 is a layout diagram of a display device according to a comparative example of the present invention. Referring to FIG. 7, most of the components of the display device of FIG. 7 are similar to the present invention, but the shape of the pixel electrode 191 of FIG. 7 is different from that of the display device of the embodiment of the present invention. That is, in the display device of FIG. 7, the first sub-pixel electrode 191a is located in region A and the second sub-pixel electrode 191b is located in region B separately.

On the other hand, in the display device according to an embodiment of the present invention, the first sub-pixel electrode and the second sub-pixel electrode are all located in the A region, and the first sub-pixel electrode and the second sub-pixel electrode are all located in the B region.

In the display device of FIG. 7, the shape of the pixel electrode is composed of a horizontal stripe portion, a vertical stripe portion 195a orthogonal thereto, and a fine edge portion extending from the horizontal stripe portion, and the lengths of the fine edge portions 193a are the same.

In this case, the control power of the liquid crystal is weakened at the boundary between the micro branches and the micro branches of the adjacent region of the vertical stem, and if the control power of the liquid crystal is weakened, it is visually recognized as a texture.

8 is an image in which a texture is generated in a display device having a pixel structure according to a comparative example of the present invention. As shown in Fig. 8, the texture appears at the boundaries where the alignment direction of the liquid crystal molecules is changed and in the vicinity of the vertical line base.

However, in the case of the display device according to an embodiment of the present invention, the length of the micro branches is different. As shown in Figs. 5 and 9, the length of the micro branches of the region adjacent to the longitudinal branch base becomes long, and the length of the micro branches generally differs. The length of the micro branches may be increased to compensate for the difference in the liquid crystal control power due to the difference in the lengths of the micro branches, and the liquid crystals may be uniformly arranged as a whole.

In the display device of FIG. 7, only the first sub-pixel electrode or the second sub-pixel electrode exists in one region A or B, and the fine branches extend in all four directions in each region. Therefore, the boundary where the arrangement of liquid crystal molecules changes is present three times.

However, in the display device according to the comparative example of the present invention, the first subpixel electrode and the second subpixel electrode exist in one region, and the fine branches extend in two directions as a whole. Therefore, the boundary where the arrangement of the liquid crystal molecules changes is present only once, which can prevent the occurrence of the texture at the boundary.

9 is an image of a display device according to an embodiment of the present invention. Referring to FIG. 9, it can be seen that the display device according to an embodiment of the present invention does not generate a texture at the boundary of the pixel electrode.

Therefore, when the liquid crystal display device according to the present embodiment is implemented as a curved display, the occurrence of a texture can be prevented, and the side view visibility in which the degree of the liquid crystal lie in one pixel region is varied can be improved.

FIG. 10 shows a result of a visibility simulation according to a display device and a comparative example according to an embodiment of the present invention. 10, the GDI index of the display device according to the comparative example of the present invention (the display device of FIG. 7) was 0.32, but the GDI index of the display device according to an embodiment of the present invention was 0.26, Of the total population.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

GL, 121: gate line RL, 131: partial voltage reference line
DL, 171: data line Clca, Clab: liquid crystal capacitor
Qa, Qb, Qc: switching element (thin film transistor)
110, 210: substrate 124a, 124b, 124c: gate electrode
140: gate insulating films 154a, 154b, 154c, 157: semiconductor
163a, 165a, 163b, 165b, 163c, 165c:
173a, 173b and 173c: source electrodes 175a, 175b and 175c: drain electrodes
180p, and 180q: protective films 191a and 191b:
220: first light blocking member 230: color filter

Claims (20)

The first substrate,
A gate line formed on the first substrate,
An insulating film formed on the gate line,
A first sub-pixel electrode and a second sub-pixel electrode including a plurality of pixel branched electrodes,
The first sub-pixel electrode and the second sub-pixel electrode each include a first region and a second region,
The first region and the second region of the first sub-pixel electrode have a polygonal shape in which two sides meet diagonally with each other. One side of the polygon not perpendicular to the diagonal line is perpendicular to the gate line,
The first and second regions of the second sub-pixel electrode are formed with grooves having a shape corresponding to the first sub-pixel electrode on one side,
Wherein the first sub-pixel electrode and the second sub-pixel electrode are connected to each other,
And a first region and a second region of the second sub-pixel electrode are connected to each other. The method of claim 1,
Wherein the first sub-pixel electrode includes a vertical portion perpendicular to the gate line, a horizontal portion perpendicular to the vertical portion connected to the vertical portion, and a plurality of fine branch portions extending in both diagonal directions from the horizontal portion, Display device. 3. The method of claim 2,
Wherein the length of the fine branching portion is the longest near the vertical branching portion, and becomes shorter as the distance from the vertical branching portion increases. 4. The method of claim 3,
Wherein vertical stripe portions of the first region of the first sub-pixel electrode and the vertical stripe portions of the second region of the first sub-pixel electrode are located opposite to each other. 4. The method of claim 3,
Wherein a vertical stripe portion of the first region of the first sub-pixel electrode and a vertical stripe portion of the second region of the first sub-pixel electrode are located on the same side. The method of claim 1,
An extension line extending across the first area of the second sub-pixel electrode is formed in the first area of the first sub-pixel electrode,
And the extension line is connected to the second region of the first sub-pixel electrode. The method of claim 6,
A first drain electrode and a second drain electrode formed on the insulating film,
And a protective film formed on the first drain electrode and the second drain electrode,
Wherein the protective film is formed with a first contact hole for exposing the first drain electrode and a second contact hole for exposing the second drain electrode,
And an extension line connecting the first region of the first sub-pixel electrode and the second region of the first sub-pixel electrode is in contact with the first drain electrode through the first contact hole. The method of claim 1,
Wherein the second sub-pixel electrode includes a vertical portion perpendicular to the gate line, a plurality of horizontal portions connected to the vertical portion and perpendicular to the vertical portion, and a plurality of fine branched portions extending in both diagonal directions from the horizontal portion Liquid crystal display device. 9. The method of claim 8,
The plurality of transverse portions in the first region or the second region of the second sub-pixel electrode are respectively located at the upper, middle, and lower portions of the respective regions,
Wherein lengths of the upper and lower transverse portions are longer than the length of the transverse portion located at the central portion. The method of claim 9,
Wherein in the first region or the second region of the second sub-pixel electrode,
And the horizontal portion located at the center portion is removed. 11. The method of claim 10,
A vertical stripe portion of the first region of the second sub-pixel electrode,
And vertical stripe portions of the second regions of the second sub-pixel electrodes are located opposite to each other. 11. The method of claim 10,
A vertical stripe portion of the first region of the second sub-pixel electrode,
And the longitudinal strip portion of the second region of the second sub-pixel electrode is located on the same side. The method of claim 1,
The first region of the second sub-pixel electrode and the second region of the second sub-pixel electrode are connected by an extension line of the second sub-pixel electrode,
The extension of the second sub-pixel electrode progresses to an outer edge of the first sub-pixel electrode, or proceeds across an area where the gate line is formed. The method of claim 1,
A first drain electrode and a second drain electrode formed on the insulating film,
And a protective film formed on the first drain electrode and the second drain electrode,
Wherein the protective film is formed with a first contact hole for exposing the first drain electrode and a second contact hole for exposing the second drain electrode,
And an extension line connecting the first region of the second sub-pixel electrode and the second region of the second sub-pixel electrode is in contact with the second drain electrode through the second contact hole. The method of claim 1,
A second substrate corresponding to the first substrate,
A common electrode formed on the second substrate,
And a liquid crystal layer disposed between the first substrate and the second substrate,
Wherein a magnitude of a voltage applied before the first sub-pixel is different from a magnitude of a voltage applied to the second sub-pixel electrode. The method of claim 1,
An alignment layer exists on the first sub-pixel electrode and the second sub-pixel electrode,
Wherein the alignment layer is formed of a pre-
Wherein a line inclination angle formed on the alignment layer on the first sub-pixel electrode is larger than a line inclination angle formed on the alignment layer on the second sub-pixel electrode. The method of claim 1,
Wherein the first sub-pixel electrode and the second sub-pixel electrode do not overlap with each other. The method of claim 1,
Wherein the liquid crystal display device is a curved display. The method of claim 1,
Wherein the first region is located above the gate line and the second region is located below the gate line. The method of claim 1,
The first region and the second region of the first sub-pixel electrode have a triangular shape,
Wherein the first region and the second region of the second sub-pixel electrode have a rectangular shape with a triangular groove corresponding to the first sub-pixel electrode on one side.

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